Microprocessor extensions for two-dimensional graphics processing

Abstract

Embodiments of the invention comprise a new device and technique to realize an improved graphics generation system. This improvement is preferably achieved by implementing an interface logic portion to interface with the CPU, a control register portion, a pixel FIFO array portion, a pixel processing logic portion, and a control logic portion. These portions are preferably implemented as an extension of the internal architecture of the CPU. The CPU may be attached to the graphics system via a data cache and a write buffer portion. Data is read from the system memory and placed in the data cache so that subsequent accesses to the same location only require access to the cache. System memory data is written to a write buffer, so that the data written may be queued up and sent to the main memory at an appropriate time. The display refresh controller also reads the data from the system memory and converts the data to a signal for output to a display.

What is claimed is:  
     
       1. An apparatus for processing graphics, comprising: 
       a central processing unit for managing graphics and outputting to a display controller,  
       a data cache memory, coupled between the central processing unit and a system bus, and  
       a graphics coprocessor coupled with the central processing unit through a connection that is free of the system bus, wherein the graphics coprocessor architecturally extends an instruction set of the central processing unit and wherein the connection comprises an interface having a control logic, a pixel processing logic, a control register, and a memory device.  
     
     
       2. An apparatus as recited in  claim 1 , wherein the graphics coprocessor accesses the data cache memory by utilizing the coupling between the graphics coprocessor and the central processing unit. 
     
     
       3. An apparatus as recited in  claim 1 , further comprising: 
       a write buffer memory, that is coupled to the system bus, and  
       a system memory device, that is coupled to the system bus, wherein data is read from the system memory device and the data is stored in the data cache, and wherein at least a portion of the data is written to the write buffer, at least a portion of the data is read from the system memory, and the read data is converted into a signal that is output to a display.  
     
     
       4. An apparatus as recited in  claim 3 , wherein 
       storing the data in the data cache is performed such that a subsequent access to a same location only requires an access to the data cache memory.  
     
     
       5. An apparatus as recited in  claim 3 , wherein writing of the data to the write buffer is performed so that a write is queued up for transmission to a main memory. 
     
     
       6. An apparatus as recited in  claim 1 , wherein the central processing unit communicates with the system bus via at least one of a data cache and a write buffer. 
     
     
       7. An apparatus as recited in  claim 1 , further comprising: 
       a main memory, wherein the central processing unit communicates with the main memory via at least one of the data cache and a write buffer.  
     
     
       8. An apparatus as recited in  claim 1 , wherein the graphics coprocessor comprises a logic extension of the central processing unit. 
     
     
       9. An apparatus as recited in  claim 1 , wherein the graphics coprocessor comprises a software extension of the central processing unit. 
     
     
       10. An apparatus as recited in  claim 1 , wherein the graphics coprocessor utilizes a data cache and write buffer utilized by the central processing unit. 
     
     
       11. An apparatus as recited in  claim 1 , wherein the graphics coprocessor is integral with the central processing unit. 
     
     
       12. An apparatus as recited in  claim 1 , wherein the control logic provides a path for returning data to the central processing unit. 
     
     
       13. An apparatus as recited in  claim 1 , wherein the control logic provides hand-shake signals to inform the central processing unit when an instruction is complete. 
     
     
       14. An apparatus as recited in  claim 1 , wherein the control register comprises a pixel count parameter. 
     
     
       15. An apparatus as recited in  claim 1 , wherein the control register comprises a bits per pixel parameter. 
     
     
       16. An apparatus as recited in  claim 1 , wherein the control register comprises a raster operation code parameter. 
     
     
       17. An apparatus as recited in  claim 1 , wherein the control register comprises a foreground color parameter and a background color parameter. 
     
     
       18. An apparatus as recited in  claim 1 , wherein the memory device is a pixel first-in-first-out (FIFO) array. 
     
     
       19. An apparatus as recited in  claim 18 , wherein pixel data is loaded into the FIFO array. 
     
     
       20. An apparatus as recited in  claim 19 , wherein the pixel processing logic processes the pixel data to render graphics. 
     
     
       21. A method for processing graphics, comprising the steps of: 
       providing a central processing unit for managing graphics and outputting to a display controller,  
       providing a data cache memory, coupled between the central processing unit and a system bus, and  
       coupling a graphics coprocessor to the central processing unit through a connection that is free of the system bus, wherein the graphics coprocessor architecturally extends an instruction set of the central processing unit and wherein the connection comprises an interface having a control logic, a pixel processing logic, a control register, and a memory device.  
     
     
       22. A method as recited in  claim 21 , further comprising the step of: 
       providing an access between the graphics coprocessor and at least one of the data cache memory and a write buffer memory by utilizing the coupling between the graphics coprocessor and the central processing unit.  
     
     
       23. A method as recited in  claim 21 , further comprising the steps of: 
       providing an access to at least one of the data cache memory and a write buffer memory by the graphics coprocessor, and  
       utilizing the coupling between the graphics coprocessor and the central processing unit to provide the access.  
     
     
       24. A method as recited in  claim 21 , wherein the graphics coprocessor utilizes a data cache and write buffer utilized by the central processing unit. 
     
     
       25. A method for processing graphics, comprising: 
       communicating data directly between a central processing unit and a graphics coprocessor, wherein the central processing unit manages graphics and outputs to a display controller via a system bus and is coupled with the graphics coprocessor via a connection that is free of the system bus;  
       accessing at least one of a data cache memory and a write buffer memory by the graphics coprocessor;  
       utilizing the coupling between the graphics coprocessor and the central processing unit to perform the accessing step; and  
       architecturally extending an instruction set of the central processing unit utilizing the coupling between the graphics coprocessor and the central processing unit and wherein the coupling comprises an interface having a control logic, a pixel processing logic, a control register, and a memory device.  
     
     
       26. A method as recited in  claim 25 , further comprising the steps of: 
       reading data from a system memory device;  
       storing the data in the data cache;  
       writing at least a portion of the data to the write buffer;  
       reading at least a portion of the data from the system memory; and  
       converting the read data into a signal that is output to a display.  
     
     
       27. A method as recited in  claim 25 , further comprising communicating between the central processing unit and a system bus via at least one of a data cache and a write buffer. 
     
     
       28. A method as recited in  claim 25 , further comprising communicating between the central processing unit and a main memory via at least one of a data cache and a write buffer. 
     
     
       29. A method as recited in  claim 25 , further comprising storing the data in the data cache such that a subsequent access to a same location only requires an access to the data cache memory. 
     
     
       30. A method as recited in  claim 25 , further comprising writing the data to the write buffer, so that a write is queued up for transmission to a main memory. 
     
     
       31. A method as recited in  claim 25 , wherein the graphics coprocessor comprises at least one of a logic extension and a software extension of the central processing unit.